As each patient’s condition is different, rehabilitation exercises should be tailored to the patient’s specific situation and a suitable individualized rehabilitation program should be developed. After ACL reconstruction, a removable brace or hinged brace should be worn for 4-6 weeks. In addition to knee rehabilitation, active activities of the adjacent joints can be started as early as possible.
Pain will exist during rehabilitation exercises and is unavoidable. If the pain diminishes or disappears within half an hour of exercise cessation, there is no tissue damage and the rehabilitation can be continued.
Muscle strength exercises should be performed throughout the rehabilitation program. Each exercise should be performed until the muscles feel sore and fatigued, and then the next set should be performed after sufficient rest. Improvement in muscle strength is a key factor in restoring joint stability and should be maintained.
The swelling of the knee joint will accompany the entire exercise process until the knee flexion and extension angles and muscle strength return to normal, then the knee swelling will gradually subside. If there is a sudden increase in knee swelling, you should adjust your exercises, reduce the amount of activity and return to the hospital for a review if necessary.
Immediately after functional exercise, ice should be applied for 15-20 minutes. If you usually feel swelling, pain and heat in the joint, you can continue to apply ice 2~3 times a day.
Phase I: 1~7 days after surgery (postoperative edema period)
Brace requirement: the knee brace is locked in 0 degree extension position. You can walk on the ground with the help of double crutches, without weight-bearing on the affected limb.
Functional exercise.
Active ankle flexion and extension exercise (ankle pump): hard, slow, full-range plantar flexion and dorsiflexion of the ankle joint can promote blood circulation and eliminate swelling, which is important to prevent the emergence of deep vein thrombosis in the lower limbs. Once a day for 2 hours, 1~2 sets of 20 each.
Isometric training: quadriceps isometric contraction, N cord muscle isometric contraction exercises
Move the patella: push the patella up and down and left and right by hand, 4 times a day, 1~2 sets each time, 4 directions per set, 15 sets each.
Straight leg raise training: after extending the knee, keep the knee joint straight and raise it until the heel leaves the bed at 10~15 cm, hold it for 30~60 seconds/time.
Exercise 3 sets per day, 20~30 times per set.
Knee mobility exercises: The affected knee is required to be able to passively straighten to 0 degrees and flex the knee at an angle of less than 90 degrees. The following methods can be used, and the principle of exercise is passive closed-chain knee flexion exercise.
Supine closed-chain knee flexion exercise: requires that the heel of the foot does not leave the bed during knee flexion and moves on the bed surface, called “closed-chain”.
You can also use the foot along the wall to slide exercise instead; or you can sit on a chair, the healthy side of the foot to assist the affected side of the knee flexion exercise.
Exercises can be performed 4 times a day for approximately 1 hour each time. You can use CPM (Continuous Passive Motion Exercise for the knee) for knee flexion and extension. 20 to 30 minutes twice daily.
Stage 2: 2 to 3 weeks postoperatively (maximally protected period)
Progress to stage 2 criteria: free control of quadriceps strength, able to do straight leg raise with relative ease
Knee joint can be fully passively straightened
Passive flexion and extension of the knee joint to 0~90 degrees
Good patellofemoral motion
Reduced swelling of the knee joint
Phase 2 exercise program: Continue the above exercises
Add prone knee flexion exercises
CAM training
Terminal knee extension muscle strength exercises: knee extension strength exercises in the range of near extension of the knee (0-20 degrees), 4 times a day, 1 to 2 sets of 20 each, with 2 minutes rest between sets.
Resistance ankle plantar flexion training: against external resistance, toes are stepped down with force .
Knee mobility exercise: passive knee flexion 0~100 degrees, active knee flexion 0~80 degrees
Foot sliding along the wall training
Standing position: straight leg raise training, hook leg training
Stage 3: Controlled walking stage (4~6 weeks after surgery)
Criteria for progression to stage 3: Active knee flexion and extension mobility 0~90 degrees
Further reduction of knee swelling
Postoperative exercise program at week 4: Patellar luxation
Passive knee flexion and extension: 0~105 degrees, active mobility: 0~90 degrees;
Prone knee flexion and standing knee flexion exercises can be performed
Plyometric exercises
Straight leg raise: resistance can be increased gradually from 0.5 pounds (or 250 grams) to 5 pounds (2.5 kg)
Hip abduction, adduction, posterior extension resistance training: resistance from 0.5 pounds (250 grams) gradually increased to 5 pounds (2.5 kg)
Micro-squats (0-30 degrees), 30 seconds each time, 20 repetitions per set, 3 sets per day
Biodex training (performed in hospital rehabilitation unit)
Active-assisted knee mobility exercises
Quadriceps multi-point isometric strength training
Multi-point isometric strength training for the N cord muscle
Weight-bearing and balance training: training under the guidance of a therapist in the rehabilitation department
Partial weight-bearing training of the affected limb in the parallel bar (starting from 25%), weight shifting training forwards and backwards, left and right
Walking in the pool 20 minutes
Power bike training 15 minutes
5~6 weeks postoperative exercise program: Knee mobility training: passive knee mobility: 0~125 degrees, active mobility: 0~105 degrees
Resistance training for the N cord muscle: resistance flexion of the knee joint
Weight-bearing and balance training: partial weight-bearing training of the affected limb in the parallel bar (50%~100%), left-right and front-back weight transfer training
Forward-backward and side-to-side stride training
Single crutch walking training
Power bike training 15 minutes
Phase 4: 7-12 weeks after surgery (mid-protection phase)
Criteria for progression to stage 4: Active knee flexion and extension mobility 0~125 degrees
Quadriceps strength loss ≤ 40% (Biodex measurements)
N cord strength loss ≤ 20% (Biodex measurement)
No significant change in KT-1000 measurement
Phase 4 exercise program: At this stage the patient was able to walk completely off crutches
Warm-up: power bike 15 min
Patellar luxation
Knee flexion and extension mobility: 0-140 degrees passive knee flexion and extension mobility, 0-120 degrees active knee flexion and extension mobility
Strength training
Single-leg heel lift: 20 sets/group
Power bike resistance training: 15 minutes
Squat training: 20 per group, 3 groups per day
Balance training: Single-leg stance training on hard ground, or using balance board training
Step-up and step-down training
Hip trainer resistance training: forward flexion, back extension, abduction, adduction
Biodex isometric endurance training for quadriceps strength (performed in a hospital rehabilitation unit)
Proprioceptive training (knee stability training)
Center of gravity transfer training
Backward walking
Gait training
Phase 5: Return to active activity phase (13-24 weeks post-op)
Criteria for progression to stage 5: Increased strength, endurance
Begin preparation for functional activities
No change on KT-1000 test
Biodex isometric test of quadriceps strength (16 weeks post-op)
Quadriceps deficit ≤ 35%, N cord deficit ≤ 6%
Phase 5 exercise program: Adaptive training: power cycling
Strength and coordination training: including isotonic muscle strength training (continue muscle strength training with open and closed chains). Progressive resistance training with resistance maintained at 70-75% of the maximum strength for seated knee extension (to be determined by the rehab therapist after measurement)
Hip trainer training
Isometric training: Start 60° and 180° strength, endurance training with Biodex
Balance and stability training: Biodex balance training, Plyometrics training: jump-up and jump-down exercises, lateral straddle exercises; Trampline balance and proprioceptive training
Treadmill step training
Flexibility training.
Knee loop exercises
Lateral movement training
Lateral or backward running, vertical jumping, rope skipping, figure 8 running, stop-and-go training
Specialized sports activities can be trained if the H/Q ratio is 80% at isokinetic assessment